Anastasios Tsonis, emeritus distinguished professor of atmospheric science at the University of Wisconsin-Milwaukee: All the interactions of humans with the environment are part of our technological evolution. During this evolution, we could not go directly from living in the dark ages to a clean energy technology. There was no other way but to use fossil fuels and other pollution-producing agents. Is this enough to ruin the planet by altering the climate system, a system that has undergone major changes throughout the ages? While we should try our best to take care of our planet, global warming is not the only urgent planetary emergency. Overpopulation, poverty, infectious diseases and the effect of globalization in spreading them, the water crisis, energy and food availability and safety, political instability and terrorism, the global economy, even cyber security, are far more urgent problems with potentially catastrophic results for humanity.